docs: def read_sealevel_pressure(self, altitude_m=0.0):
          """Calculates the pressure at sealevel when given a known altitude in
          meters. Returns a value in Pascals."""
          pressure = float(self.read_pressure())
          p0 = pressure / pow(1.0 - altitude_m/44330.0, 5.255)
          self._logger.debug('Sealevel pressure {0} Pa'.format(p0))
          return p0